So the 18 x 10 ET25 will fit an stock ZCP E92 M3 (all 4 corners) without any spacers or modification needed? Also are the wheels hubcentric (do not require hubcentric rings)?

The e9x M3 with OEM suspension can utilize the 18x10" ET25 ARC-8 with 275/35/18 street tires without the need of any spacers. If you are using an extreme summer tire, such as a Hankook RS3 or Dunlop DZII, you may have slight rubbing on the fender liner at full lock. The wheels are hubcentric so you will not need any hubcentric rings. Let us know if you have any other questions!